Introduction
A single malformed payload can bring down a critical secrets management cluster, disrupting authentication and automation workflows across an entire organization. CVE-2025-6203 highlights the ongoing risk of resource exhaustion attacks in widely deployed infrastructure tools.
HashiCorp Vault is a leading open source and commercial secrets management solution, used by thousands of organizations to secure credentials, API keys, and encryption material. Vault is a foundational component in many cloud-native and DevOps environments, making vulnerabilities in its core request handling logic highly impactful.
Technical Information
CVE-2025-6203 is a denial of service vulnerability affecting HashiCorp Vault. An attacker can submit a specially crafted complex payload that stays within the default request size limit. When processed, this payload causes Vault to consume excessive memory and CPU resources. The impact is a timeout in the auditing subroutine, which may render the Vault server unresponsive.
The root cause is insufficient resource allocation controls in Vault's request processing pipeline, as described by CWE-770 (Allocation of Resources Without Limits or Throttling). This allows a small but complex input to trigger disproportionately high resource usage. No public code snippets or proof of concept are available for this issue.
Affected Systems and Versions
- HashiCorp Vault Community Edition prior to 1.20.3
- HashiCorp Vault Enterprise prior to 1.20.3, 1.19.9, 1.18.14, and 1.16.25
- All default configurations are vulnerable unless patched
Vendor Security History
HashiCorp Vault has experienced several high-severity vulnerabilities in 2025, including remote code execution (CVE-2025-6000), user lockout bypass (CVE-2025-6004), and privilege escalation issues. HashiCorp typically issues patches and advisories quickly, maintains transparent communication, and acknowledges external security researchers. However, the recurrence of resource exhaustion and input validation flaws suggests ongoing architectural challenges in Vault's core logic.